ResInsight/ApplicationLibCode/Application/Tools/Telemetry/RiaOpenTelemetryManager.h

/////////////////////////////////////////////////////////////////////////////////
//
//  Copyright (C) 2025- Equinor ASA
//
//  ResInsight is free software: you can redistribute it and/or modify
//  it under the terms of the GNU General Public License as published by
//  the Free Software Foundation, either version 3 of the License, or
//  (at your option) any later version.
//
//  ResInsight is distributed in the hope that it will be useful, but WITHOUT ANY
//  WARRANTY; without even the implied warranty of MERCHANTABILITY or
//  FITNESS FOR A PARTICULAR PURPOSE.
//
//  See the GNU General Public License at <http://www.gnu.org/licenses/gpl.html>
//  for more details.
//
/////////////////////////////////////////////////////////////////////////////////

#pragma once

#include <QObject>

#include <atomic>
#include <chrono>
#include <functional>
#include <map>
#include <memory>
#include <mutex>
#include <queue>
#include <stacktrace>
#include <string>

class QString;
class QNetworkAccessManager;
class QTimer;

//==================================================================================================
//
// OpenTelemetry Manager for ResInsight
// Handles async telemetry reporting with privacy filtering and resilience
//
//==================================================================================================
class RiaOpenTelemetryManager : public QObject
{
public:
    // Error handling
    enum class TelemetryError
    {
        ConfigurationError,
        NetworkError,
        AuthenticationError,
        QuotaExceeded,
        PrivacyViolation,
        InternalError
    };
    using ErrorCallback = std::function<void( TelemetryError, const QString& details )>;

    // Health monitoring
    struct HealthSnapshot
    {
        uint64_t                              eventsQueued{ 0 };
        uint64_t                              eventsSent{ 0 };
        uint64_t                              eventsDropped{ 0 };
        uint64_t                              networkFailures{ 0 };
        std::chrono::steady_clock::time_point lastSuccessfulSend;
        std::chrono::steady_clock::time_point systemStartTime;

        double getSuccessRate() const;
        bool   isHealthy() const;
    };

    struct HealthMetrics
    {
        std::atomic<uint64_t>                 eventsQueued{ 0 };
        std::atomic<uint64_t>                 eventsSent{ 0 };
        std::atomic<uint64_t>                 eventsDropped{ 0 };
        std::atomic<uint64_t>                 networkFailures{ 0 };
        std::chrono::steady_clock::time_point lastSuccessfulSend;
        std::chrono::steady_clock::time_point systemStartTime;
    };

    static RiaOpenTelemetryManager& instance();
    static QString                  getSystemUsername();

    bool initialize();
    void shutdown();
    bool reinitialize();

    // Event reporting
    void reportEventAsync( const std::string& eventName, const std::map<std::string, std::string>& attributes );
    void reportCrash( int signalCode, const std::stacktrace& trace );

    // Configuration
    bool isEnabled() const;
    bool isInitialized() const;
    void setErrorCallback( ErrorCallback callback );
    void setUsername( const std::string& username );

    // Performance and memory management
    void   setMaxQueueSize( size_t maxEvents );
    void   enableBackpressure( bool enable );
    void   setMemoryThreshold( size_t maxMemoryMB );
    size_t getCurrentQueueSize() const;

    // Health monitoring
    HealthSnapshot getHealthMetrics() const;
    bool           isHealthy() const;
    void           enableHealthMonitoring( bool enable );

private:
    RiaOpenTelemetryManager();
    ~RiaOpenTelemetryManager() override;

    RiaOpenTelemetryManager( const RiaOpenTelemetryManager& )            = delete;
    RiaOpenTelemetryManager& operator=( const RiaOpenTelemetryManager& ) = delete;

    struct Event
    {
        std::string                           name;
        std::map<std::string, std::string>    attributes;
        std::chrono::system_clock::time_point timestamp;

        Event( const std::string& eventName, const std::map<std::string, std::string>& attrs )
            : name( eventName )
            , attributes( attrs )
            , timestamp( std::chrono::system_clock::now() )
        {
        }
    };

    // Initialization
    bool initializeProvider();
    bool createExporter();
    void setupResourceAttributes();

    // Event processing
    void processEvents();
    void processEvent( const Event& event );
    void flushPendingEvents();
    void onProcessEventTimer();

    // Circuit breaker and resilience
    void handleError( TelemetryError error, const QString& context );
    void attemptReconnection();
    bool isCircuitBreakerOpen() const;
    void resetCircuitBreaker();

    // Event filtering
    bool isEventAllowed( const std::string& eventName ) const;

    // Health monitoring
    void updateHealthMetrics( bool success );
    void sendHealthSpan();

    // Thread safety
    mutable std::mutex m_configMutex;
    mutable std::mutex m_queueMutex;
    std::queue<Event>  m_eventQueue;

    // State
    std::atomic<bool> m_initialized{ false };
    std::atomic<bool> m_enabled{ false };
    std::atomic<bool> m_isShuttingDown{ false };
    std::atomic<bool> m_circuitBreakerOpen{ false };

    // Qt networking and timer
    QNetworkAccessManager* m_networkAccessManager{ nullptr };
    QTimer*                m_processTimer{ nullptr };
    QTimer*                m_healthTimer{ nullptr };

    // Configuration
    size_t      m_maxQueueSize{ 10000 };
    bool        m_backpressureEnabled{ true };
    size_t      m_memoryThresholdMB{ 50 };
    std::string m_username;

    // Error handling
    ErrorCallback                         m_errorCallback;
    std::atomic<int>                      m_consecutiveFailures{ 0 };
    std::chrono::steady_clock::time_point m_lastReconnectAttempt;

    // Health monitoring
    mutable HealthMetrics m_healthMetrics;
    bool                  m_healthMonitoringEnabled{ false };
};